Arduino, LED strip, MOSFET, PWM - why is the transformer noisy?

Question

Arduino

The LED strip is connected through a field-effect transistor, similar to the figure (I only have R1 at 100 ohms).

When the duty cycle is 100% (analogWrite(255)), then everything is fine, there is no noise. If you do less, then the power supply starts to make noise (filmed here ).
Power supply for 2.5 But this one
I tried to put more powerfully on 5A ( such ), it also makes noise.
It was I who connected the tape 5 meters long. I also have a piece of 0.5 meters - it does not make noise with it.

Answer 1

- the noise is normal, there are no special "deviations" - bp is standard rubbish, they can whistle at any load. determined by the quality of the transformer and/or inductor at the output.
-Initially, the suffering of Andrunno users is one of the features, by design, written back in the time of the New Testament corrections. retribution for the bydlokod "analogwrite" and similar vyrviglazny creativity - is the whistle of loads at any quality bp. even by taking a pack of low-frequency ripple capacitors in the source, you can get the same exhaust from the load itself.